Improvement in registering steam-gage



UNITED STATES PATENT OEEIGE.

ELIJAH CLARK, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO UNITED STATES STEAMGAGE COMPANY, OF SAME PLACE.

IMPROVEMENT IN REGI'STERING STEAM-GAGE.

Specification forming part of Letters Patent No. 101,583, dated April 5,1870.

To all whom it may concern:

Be it known that I, ELIJAE CLARK, of Louisville, in the county ofJefferson and State of Kentucky, have invented a new and ImprovedSteam-Pressure Gage and Detecter; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanying drawings, making a part of thisspecification, in .which- Figure l is a plan view, and Fig. 2 is adiametrical transverse section.

This invention has for its main object to prevent engineers from raisingthe pressure of steam upon their boilers beyond a certain fixed limit.

To this end the invention consists in an apparatus connected with thepressuregage that both registers the number of times the index haspassed the xed limit, and also registers the highest point the index hasreached, said apparatus being, as is usual, inclosed within a locked andsealed box, which prevents the engineer from tampering with it, so thatthe owner or other person in authority can instantly perceive when hisvessel comes in from a trip whether at any time during the same, and howoften and how much, the engineer has carried steam beyond the prescribedi limit.

In the drawings, Ais the hollow knobfthat receives steam direct from theboiler and transmits it to the spring B, placed within theinclosing-case C, that is covered by the dialplate D. This spring isrendered inaccessible to water by a passage leading from the chamber tothe exterior of the knob A, which confrom the arm b, that receives thethrust of the spring and communicates the same to the index-iinger F,which set-screw is moved to one side when the spring is undergoing apressure above that prescribed as the maximum, the set-screw being soplaced that not till such a pressure is brought to bear upon the springdoes the pin b reach it.

An arm, c, pivoted to the opposite extremity of the lever a, and havinga pointed end, which is kept by a spring in contact with theratchetwheel d, the teeth of which are numbered from 1 to 3l,consecutively, and which is connected with a spring-detent, e, themoving aside of the set-screw a before described having the effect towithdraw the arm c from the ratchet d, which arm returns to the ratchetagain and moves it by the space of one tooth every time the pin bwithdraws from contact with the setserew, so that the figure inscribedupon that tooth of the ratchet-wheel against which the arm c bearsindicates infallibly how many times steam has run above the limit ofpressure, a small space being left between the first and last teethofthe ratchet d, to the end that, should the misconduct of the engineerever be so great as to bring the arm c to the last tooth, it would beout of his power to wipe out the record against him by running theratchet on till the arm c was again in contact with tooth No. l, theonly thing to be done after reaching the last tooth being to unlock thebox and reset the register, which, as was before explained, the engineercannot do.

An arm, e, having near one end a slot, e', through which passes a pinprojecting upward from the lever a, and jointed at its other extremityto one side of a disk, 71 whose axis is the shaft of the index-finger F,from another point of the edge of which disk projects a smallerindex-Enger, 1', which extends over a scale, G, 011 the inner edge ofthe dial-plate, which scale is divided into ten equal parts, each ofwhich indicates ten pounds of pressure, so that if the pin b moves theset-screw a so far to one side as to cause the lever a to draw, by meansof the connecting-arm e, the finger 11 over a portion of the scale G,that portion indicates the number of pounds excess over the limit ofpressure which has been attained.

The index-fin ger i never goes back, nor does Y scribed limit.

2. The combination of the lever a, connecting-rod e, disk h, andindeX-nger i with the lever b, or such other part of the pressure-gagemechanism as receives the thrust of the spring,` B, substantially in themanner described, and for the purpose of recording the excess ofpressure above the prescribed limit.

E. CLARK.

Witnesses:

FRED. WEBBER, J. E. PimmsoN,v WM. H. LEATHERMAN.

